1. Field of the Invention
The present invention relates to a storage control device.
2. Description of the Related Art
The storage control device comprises a storage section obtained by connected a multiplicity of hard disk drives in the form of an array and provides a host computer such as a server (‘host’ hereinbelow) with a logical storage region (logical volume). In order to improve reliability, the storage control device provides the host with a RAID (Redundant Array of Independent Disks)-based redundant storage region.
Further, the data to be managed by an enterprise or the like grows day by day. Hence, a storage control device capable of increasing the storage capacity in accordance with the increase in the amount of data is preferable. Therefore, a storage control device that is able to provide a storage region that matches the user's needs by connecting a plurality of additional enclosures that provide storage regions to the base enclosure governing the control function has been proposed (Japanese Patent Application Laid Open No. 2001-339853).
In the conventional technology appearing in Japanese Patent Application Laid Open No. 2001-339853, the start or stoppage of the power supply to the base enclosure and the start or stoppage of the power supply to each additional enclosure are made to work together. As a result, when the storage control device is stopped completely, the whole of the power supplied to the respective enclosures can be automatically stopped simply by stopping the power supply to the base enclosure.
In further conventional technology that appears in Japanese Application Laid Open No. 2000-293314, the respective magnetic disk devices that constitute a RAID group are shifted to power conservation mode.
In the conventional technology that appears in Japanese Patent Application Laid Open No. 2001-339853, the power supply operation to the base enclosure and the power supply operation of each additional enclosure are made to work together but the results are limited from the perspective of reducing the power consumption of the storage control device.
On the other hand, in the case of the conventional technology that appears in Japanese Application Laid Open No. 2000-293314, the power consumption of the storage control device can be reduced because the magnetic disk devices which cannot be accessed at fixed intervals are shifted to power conservation mode.
However, in the case of the conventional technology that appears in Japanese Application Laid Open No. 2000-293314, the power consumption amount of the respective magnetic disk devices constituting the RAID group remains curtailed and there is scope for additional improvement. That is, even when the respective magnetic disk devices are moved to power conservation mode, power is supplied to the control circuit section and cooling fan in the enclosure and to the power supply circuit and the operation is continued. Hence, there is scope for improvement in the power consumption of each section other than the magnetic disk device.